Starship Asterisk*

Sun with Solar Flare

Explanation: This week the Sun gave up its strongest solar flare so far in 2013, accompanied by a coronal mass ejection (CME) headed toward planet Earth. A false-color composite image in extreme ultraviolet light from the Solar Dynamics Observatory captures the moment, recorded on April 11 at 0711 UTC. The flash, a moderate, M6.5 class flare erupting from active region AR 11719, is near the center of the solar disk. Other active regions, areas of intense magnetic fields seen as sunspot groups in visible light, mottle the surface as the solar maximum approaches. Loops and arcs of glowing plasma trace the active regions' magnetic field lines. A massive cloud of energetic, charged particles, the CME will impact the Earth's magnetosphere by this weekend and skywatchers should be on the alert for auroral displays.

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Uh-oh! DUCK!! ... Then look towards the north... Unless you live there, in which case you'll probably get a stiff neck from looking up.

That's a beautiful image. Do the crew of the ISS need to go into a shielded shelter for this?

Ash, "Picachu, Electroball...NOW!!!"

I hope it is not a bad bout of electro-magnetic disturbance. I have shows I record on the weekend....

:---[===] *

The flare looks like it is not quite aimed at Earth. Will it hit Earth because it spreads out a lot? Or is it because it is leaving the surface of the sun at an angle other than 90 deg.?

FLPhotoCatcher wrote:
The flare looks like it is not quite aimed at Earth.
Will it hit Earth because it spreads out a lot?
Or is it because it is leaving the surface of the sun at an angle other than 90 deg.?

• Because it spreads enough.

A coronal mass ejection in time-lapse imagery obtained with the LASCO instrument. The Sun (center) is obscured by the coronagraph's mask. (September 30 – October 1, 2001)

What can we do about it; besides watch the upcoming aurora?

orin stepanek wrote:
What can we do about it; besides watch the upcoming aurora?

http://www.defencetalk.com/forums/military-strategy-tactics/complete-u-s-army-manual-1496/ wrote:
[list]REACTING TO FLARES[/list]<<Hit the ground (behind cover if possible). If moving where it is easy to blend with the background (such as in a forest) and you are caught in the light of an flare, freeze in place until the flare burns out. If you are caught in the light of an flare while moving in an open area, immediately crouch low or lie down. If you are crossing an obstacle, such as a barbed-wire fence or a wall, and get caught in the light of an flare, crouch low and stay down until the flare burns out. The sudden light of a bursting flare may temporarily blind both you and the enemy. When the enemy uses a flare to spot you, he spoils his own night vision. To protect your night vision, close one eye while the flare is burning. When the flare burns out, the eye that was closed will still have its night vision.>>

I suggest to use a selfmade tinfoil hat, like a giant sombrero hat, so you can hide under it when flares come close enough to get you!

A stunning photo of the awesome power of Sol.

Art, we're in the good zone!

Thank you thank you thank you! But from where to watch?

prominence perseveringly pictured

earthbound and down

neufer wrote:

Click to view full size image

Bear in mind that much of the "not visible" area may still show faint auroras, and very likely will show photographic auroras- ones that will show nicely if you aim your camera at the northern horizon (if it's fairly dark) and make a 30 second exposure.

I'm gonna try to view the aurora throughout the night but I have my doubts about being able to see them here with the glow of the city. I'll try with the camera too. I'd make Pat go out to the relative darkness with me but he's in DC at the moment.. ugh!

Why would the good zone be south of a poor zone?

stephen63 wrote:Why would the good zone be south of a poor zone?

The region of maximal auroral activity is an oval, centered over the magnetic pole and pushed by the Sun towards midnight. This is further modified by more local magnetic conditions, and by the time that the high energy particles arrive. So the greatest aurora is typically found at some latitude south of the pole, and some longitude determined by the position of the Sun when the particles hit.

Accuweather's Facebook page said the Bz monitor has to read strongly negative before we see any aurora down south. It seems to be moving that direction...
http://www.swpc.noaa.gov/SWN/

Completely overcast here now. Doubt it will lift anytime soon. Mission aborted!

About 12:45am i had almost clear skies, but didn't see any aurora at all from the N/E corner of Connecticut.

Seems like the CME didn't have as big an impact on us as predicted.

The information brought up through the "This week the Sun" link had an image that seems to be the same as the APOD. In the caption to the linked image it states "NASA's Solar Dynamics Observatory captured this image of an M6.5 class flare at 3:16 EDT on April 11, 2013", which will be 07:16 under Universal Time (UT). In the explanation to the APOD it however states the image was recorded "at 0711 UTC". My understanding is that EDT is the Eastern Daylight Time zone in mainland United States and is 4 hours behind UT and that for general use Universal Coordinated Time (UTC despite the differing order of letters) is the same as UT, so I wonder if the time in the explanation is a mistyping? Unless I misunderstand UTC I believe even where very precise times are needed there will still be nothing like as much as 5 minutes difference (even allowing for rounding off of times).

A bit belatedly, I noticed only today something round, just beyond the limb of the Sun at about 10 - 11 o'clock. Could it be Mars?? Or is it an eruption?
Margarita

Is this the part you mean? Doesn't look very planetary to me. I think it's just a blob of the Sun's atmosphere trying to escape. It probably didn't succeed.
Rob